A reinforced soil structure combines a compacted fill, a facing and reinforcements usually connected to the facing.
Various types of reinforcement can be used: metal (for example galvanized steel), synthetic (for example based on polyester fibers), etc. They are placed in the earth with a density that is dependent on the stresses that might be exerted on the structure, the thrust of the soil being reacted by the friction between the earth and the reinforcements.
The facing is usually made from prefabricated concrete elements, in the form of panels or blocks, juxtaposed to cover the front face of the structure.
There may be horizontal steps on this front face between various levels of the facing, when the structure incorporates one or more terraces. In certain structures, the facing may be built in situ by pouring concrete or a special cement.
It is well known in the art that the facing has to be compressible in order to follow the possible deformations of the structure due to the contraction of the fill for example.
Usually, prefabricated concrete facing elements do not offer a sufficient compressibility to follow the contraction of the fill. In order to improve the situation, a method consists in introducing a compressive material between successive facing elements. In such case, the vertical soil structures are limited to around 20 meters height with a high quality fill material compacted according to the state of the art methods.
There is a need of reinforced soil structure with vertical walls of important height, particularly in quarries and mining exploitations.